Apparatus and methods for control of waste treatment processes
View Patent ↗Waste-treatment processes are enhanced through generation and introduction of specific biological populations customized to perform or favor specific tasks either during the main process, for the formation or precipitation of certain biological nutrients, or to accomplish solids formation reduction in a post-treatment process. These bacteria may be grown from specialized mixes of activated sludge and waste influent by exposing these materials to controlled environments (e.g., in an off-line treatment area). They may then be returned to the main process to perform certain tasks such as converting particulate cBOD into soluble cBOD for utilization, to reduce high solids yield organisms by supplementing the population characteristics with low yield organism characteristics, to provide biological nutrients or oxygenation assistance, to improve nitrification/denitrification efficiency, or to disfavor filamentous biology such as Norcardia sp.
1. A method of treating a waste stream, the method comprising the steps of:
a. conducting at least a portion of the waste stream to a first treatment vessel for treatment comprising contact with a first biological population having a first population profile;
b. drawing off a portion of the waste stream to an off-line treatment vessel; and
c. controlling the drawn-off portion of the waste stream in the off-line treatment vessel so as to establish, in the drawn-off portion, a second biological population having a second population profile different from the first population profile, and repeatedly solubilizing and precipitating phosphate to create phosphate particles having increasing size wherein, during the controlling step, there is no flow from the off-line treatment vessel to the first treatment vessel.
2. The method of claim 1 wherein, in the controlling step, the solubilizing and precipitating of phosphate comprises:
a. controlling an ORP level in the drawn-off portion in the absence of aeration and mixing thereof to obtain a reduced pH level to solubilize phosphate from phosphorous-based alkalinity; and
b. precipitating the solubilized phosphate out of solution by aerating the drawn-off portion to increase a pH level thereof.
3. The method of claim 2 further comprising, during step (a), causing generation of biologically available carbon through extracellular solubilization and cell destruction thereby enhancing a phosphorus-uptaking capacity of at least a portion of the second biological population when re-aerating the mixture.
4. The method of claim 2 wherein the controlling step includes allowing settling to produce a decantable volume having a reduced biological phosphate content.
5. The method of claim 4 further comprising the step of returning a fraction of the drawn-off portion to the first treatment vessel following contact with the second biological population, the returned fraction including a portion of the second biological population being enhanced for biological phosphorus uptake, the fraction of the drawn-off portion conducted to the first treatment vessel being taken from the decantable volume.
6. The method of claim 4 wherein an amount of treatment chemical required for subsequent removal of phosphate from the decantable volume is reduced.
7. The method of claim 6 wherein the PAO phosphorus content in at least a portion of the decantable volume is reduceable.
8. The method of claim 1 wherein solubilizing and precipitating of phosphate is facilitated by the addition of carbon dioxide.
9. The method of claim 8 wherein the carbon dioxide is introduced through respiration of a biomass.
10. The method of claim 9 wherein the biomass comprises the second biological population.
11. The method of claim 1 wherein step (d) comprises altering an ORP level in the drawn-off portion in a predetermined cyclical pattern to create chemically precipitated phosphorus particles having increasing size, the particles being resistant to release into a liquid component of the waste stream in the first treatment vessel upon return of a fraction of the drawn-off portion to the first treatment vessel following contact with the second biological population.
12. The method of claim 1 wherein step (d) comprises altering an ORP level in the drawn-off portion in a predetermined cyclical pattern to facilitate carbon utilization by the PAO, thereby enhancing the second biological population for biological uptake of phosphorus in the first treatment vessel upon return of a fraction of the drawn-off portion to the first treatment vessel, the phosphorus being released into a liquid component of the waste stream following contact with the first biological population.
13. The method of claim 1 , wherein the controlling step comprises a controlled addition of a further portion of the waste stream into the off-line treatment vessel.
14. A method of treating a waste stream, the method comprising the steps of:
a. conducting at least a portion of the waste stream to a first treatment vessel for treatment comprising contact with a first biological population having a first population profile;
b. drawing off a portion of the waste stream to an off-line treatment vessel;
c. isolating the drawn-off portion of the waste stream; and
d. controlling the drawn-off portion of the waste stream in the off-line treatment vessel so as to establish, in the drawn-off portion, a second biological population having a second population profile different from the first population profile, and repeatedly solubilizing and precipitating phosphate to create phosphate particles having increasing size, wherein, during the controlling step, there is no flow between the off-line treatment vessel and the first treatment vessel.